Charging device for gas operated firearm



July 3, 1956 c. E. SIMPSON CHARGING DEVICE FOR GAS OPERATED FIREARM Filed March 13, 1953 Impsun 2,752,826 Patented July 3, 1956 CHARGING DEVICE FOR GAS OPERATED FIREARM Clarence E. Simpson, Wilbraham, Mass, assignor to the United States of America as represented by the Secretary of the Army Application March 13, 1953, Serial No. 342,303

12 Claims. (Cl. 89-191) (Granted under Title 35, U. S. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to automatic firearms having longitudinally reciprocating bolts and relates more particularly to charging-means therefor.

In gas-operated automatic firearms of the type wherein the operating rod actuates a sprocket type feeding mechanism to advance linked cartridges in the feedway and is also the means for unlocking the bolt from battery position and accelerating it to recoil position, difliculty has been encountered in the past in providing a charging mechanism which is simple and compact. This is because there is not suflicient acceleration imparted to the bolt by the normal operation of the firing mechanism through manual charging means, to send the bolt to full recoil position in the receiver. Therefore, the bolt must be recoiled by means, additional to those provided for actuating the feeding mechanism, and cooperate therewith.

It is, therefore, an object of this invention to provide a means for initially charging an automatic firearm in i which the operating rod is the means for operating the feeding mechanism and for accelerating the bolt to recoil position.

It is another object of this invention to provide a means for charging an automatic firearm in which the bolt recoils a greater distance than the operating rod by which it is accelerated.

It is a further object of this invention to provide for automatic firearms of this type a longitudinally reciprocating charging mechanism wherein the greater pull is required in the initial movement of the charging mechanism, when the operating rod is being retracted, and less during the remainder of the movement after the operating rod has been disengaged and the bolt alone is recoiled.

It is a still further object of this invention to provide for automatic firearms a charging mechanism wherein the operating handle is identical with the front hand guard of the weapon so that the operator may charge the weapon when in firing position and without having to remove his hand from the front support of the weapon.

It is a specific object of this invention to provide a simple, rugged and compact charging mechanism for automatic firearms, of the type wherein the bolt recoils a greater distance than the accelerating operating rod and includes means for initially engaging the operating rod and subsequently disengaging it to permit further retraction of the bolt.

' The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

Fig. l is a fragmentary, longitudinal, sectional view of the front end of a firearm incorporating the charging mechanism of this invention and shows the mechanism in the forward, inoperative position;

Fig. 2 is a fragmentary, longitudinal, sectional view of the parts of the charging mechanism which retract the operating rod of the firearm and shows the operating rod drawn rearwardly and about to be disengaged from the handle means of the charging mechanism;

Fig. 3 is a fragmentary, longitudinal, sectional view of the parts of the mechanism which retract the bolt of the, firearm and shows the parts in forward, inoperative position;

Fig. 4 is similar to Fig. 3 but shows the bar for retracting the bolt engaged by the handle means of the charging mechanism during the charging operation; and

Fig. 5 is a cross-sectional view taken along line 5-5 of Fig. l. i

Referring to the drawings, there is illustrated a firearm having a barrel 12 and a receiver 13 with a longitudinally reciprocating bolt 14 mounted therein. Bolt 14 is of twopiece type and includes a head member 8 and an extension member 9 mounted for limited slidable movement thereon as more fully described in Patent No. 2,651,974 issued to applicant September 15, 1953. Arranged above barrel 12 and parallel therewith is a longitudinal gas cylinder 17, the rear end of which communicates with the forward portion of receiver 13. Provided below barrel 12, in parallel relationship with such barrel and cylinder 17, is a tubular member 18, the rear end of which is secured to receiver 13. v The front ends of cylinder 17 and tubular member 18 are joined by a bracket 16 that encircles barrel 12 adjacent a gas port (not shown) through which gases are bled from the bore of barrel 12 to the forward end of cylinder 17.

Slidablyaccommodated in cylinder 17 is a cooperating unitary piston and operating rod member 21 which extends rearwardly into receiver 13 to contact the front end of a slidably arranged bolt lock actuator 19. The rear end of actuator 19 contacts the front end of bolt extension member 9 when bolt 14 is in battery position. Thus, when operating rod 21 is recoiled during fire, the acceleration thereof is imparted. to bolt 14 through actuator 19. Also during the recoil of actuator 19, bolt head member 8 is unlocked from battery position while bolt extension member 9 is being accelerated rearwardly by such actuator and is in slidable relationship with such bolt head member by means fully described in the aforementioned patent. Provided on the top rear portion of operating rod 21 is an upstanding lug 22 which engages a helical slot 23 in a driving shaft 24 to drive a feeding mechanism (not shown).

A longitudinal, cylindrical bore 26 extends forwardly from the rear end of operating rod 21 to a vertical slot 27 therethrough. Passing transversely through slot 27 is a' pin 28 on which there is pivotally mounted an actuating pawl 29. Pawl 29 is formed by a rectangular body portion 46, and a downwardly depending lug portion 48. Body portion 46 is provided with a central hole 47 which receives pin 28 and lug 48 is provided with a forwardly engaging head 39 and a cam portion 49 rearwardly adjacent thereto. Provided in the underside of cylinder 17 is a longitudinal slot 30 arranged to receive lug 48 therethrough when operating rod 21 is in a forward position.

Also accommodated in cylindrical bore 26, rearwardly of pawl 29, is a slidable rod member 31 and a coiled compression spring 32 which contacts rod 31 at one end and receiver 13 at the other. Spring 32 cooperates by urging operating rod 21 forwardly in cylinder 17 and simultaneously urging rod 31 forwardly against pawl-'29. The engagement of the front face of rod 31 with the rear face of pawl 29 maintains lug 48 resiliently downward through slot 30. 1

Slidably mounted on tubular member 18 is a sleeve member 33. Secured tosleeve 33 and extending downwardly therefrom is a substantially rectangular box-like hand guard member 43, which acts as the front hand guard for the firearm and the handle for the charging mechanism. Provided laterally through the forward portion of hand guard 43 is a spring-biased latch 44- which engages tubular member 18 in full forward position. Accommodated in tubular member 18 is a coiled compression spring 34 which contacts the rear wall thereof at one end and a slidable rod member 38 at the other. Sleeve member 33 is secured to rod member 33 hv a pin 36 which passes through a longitudinal opening 35 in tubular member 18.

Provided on sleeve 33 is a bracket 41 having an arm 37 which encircles one side of barrel 12 to slidably contact the bottom side of cylinder 17 forwardly adiacent engaging head 39. Provided along one side of bracket 41 is a longitudinal slideway 49 which stops short of the rear end thereof to form a raised rectangular portion 50. A substantially L-shaped guide portion 51 eatends from bracket 41 over the rear end of slideway 49 to form therewith an undercut channel 52. Slidably mounted in undercut channel 52 is a rectangular bar 42 which extends rearwardly through an opening in the front end of receiver 13 to contact a shoulder 7 on bolt head member 8. A toe portion 57 on the rear end of bar 42 assures contact thereof with shoulder 7. A rectangular notch 54 in the top side of bar 42 is arranged to mate with guide 51 and another rectangular notch 56 is provided in the side of slideway 49 to mate with the rear lug 55, thus permitting bar 42 to be aligned with undercut channel 52 when moved laterally thereinto when assembling. Provided on bar 42 are a pair of spaced apart lugs 55 which limit the reciprocal movement of bar 42 in undercut channel 52. The rear lug 55 is so arranged that bar 42 is in slidable relationship with bracket 41 while bar 42 is held stationary by locked bolt head member 8 and is engaged by rectangular portion 51) when bolt head member 8 is unlocked from battery position.

To operate the charging device of this invention, latch 44 is actuated to release hand guard 43 from tubular member 18. Hand guard 43 is then pulled rearwardly, moving sleeve member 33 along tubular member 18 to en gage arm 37 thereon with engaging head 39 of pawl 29 and thereby moving operating rod 21 also rearwardly. Operating rod 21 performs during the rearward move ment all the functions performed thereby during recoil in fire; that is, it rotates feeding mechanism (not shown) by means of the engagement of lug 22 in helical slot 23 of driving shaft 24 to index a cartridge in the feedway of receiver 13 and moves actuator 19 to unlock bolt 14 from battery position and initiate the recoil thereof. However, there is not sufficient acceleration imparted to actuator 19 by the manual operation of operating rod 21, to fully recoil bolt 14, which moves in recoil a greater distance than does operating rod 21. Bolt 14 is further recoilcd by the mechanism of this invention as follows:

As pawl 29 is moved rearwardly in slot 30 of cylindrical member 17, by the pull on hand guard 43, cam 4-9 contacts the rear wall of slot 30 when operating rod 21 nears the rearward limit of travel. As shown in Fig. 2, continued rearward movement of cam 40 against the rear wall of slot 30 urges the extending lug portion 48 of pawl 29 upwardly into slot 27 in operating rod 21, cansing engaging head 39 to move out of engagement with arm 37 by the time operating rod 21 reaches full recoil position. Hence, operating rod 21 is free to re turn to full forward position under the bias of spring 32 and hand guard 43 is free therefrom to be retracted further along tubular member 18. At the same time, the upward pivotal movement of lug portion 43 of pawl 29 around pin 28 has caused the top rear corner of body portion 46 to move rearwardly, urging rod 31 against spring 32. The spring bias of rod 31 against the rearwardly projecting corner of pawl 29 returns pawl 29 to normal position, relative to slot 27, when operating rod 21 returns forwardly, and ready to be reengaged by arm 3:? when hand guard 43 is returned to full forward position.

During the initial rearward movement of hand guard 43, bar 42 is held stationary against shoulder 7 of bolt head member 8, which is locked in battery position. However, hand guard 43 is retractable because of the slidable engagement of bar 42 with bracket 41 and by the time that hand guard 43 is moved to where raised rectangular portion 5 contacts the rear lug 55, bolt head member 8 has been unlocked. Further pressure of rectangular portion Si; against rear lug 55 moves bar 4-2 rearwardly against bolt head member 8 to retract bolt 14 to full recoil position by the time that hand guard 43 reaches the rearmost limit of travel on tubular member 18. During the rearward movement of sleeve 33 along tubular member 1?}, spring 54- therein is compressed by means hereinbefore explained and thereby resiliently rcturns hand guard to full forward position after the firearm has been charged. In the return of hand guard 43, rectangular portion 56 engages the rent lug 55 to return bar 42 to forward position.

It is clearly evident that there is here provided a simple, rugged and. compact charging mechanism for a firearm of the type wherein the operating rod recoils a longitudinally reciprocating bolt and operates the feeding mechanism.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

I claim:

1. A charging mechanism for a firearm having an operating mechanism reciprocable between a forward position and a retracted position and a reciprocable bolt having engagement with the operating mechanism during movement thereof to the retracted position so as to be energized for continued movement to a recoil position after the operating mechanism reaches the retracted position, said charging mechanism comprising a handle reciprocable between a forward and a rearward position, a pawl pivotally mounted to the operating mechanism for engagement by said handle during movement to the rear ward position to transmit rearward movement of said handle to rearward movement of the operating mechnism, cam means for disengaging said pawl from said handle when the operating mechanism is in the retracted position, a spring biased against said pawl for simultaneously biasing said pawl to the position to be engaged by said handle and the operating mechanism to the forward position, and means cooperating with said handle and the bolt for movement of the bolt to the recoil position by said handle after the operating mechanism is disengaged therefrom.

2. A charging mechanism for a firearm having an operating mechanism reciprocable between a forward position and a retracted position and a reciprocable bolt and having engagement with the operating mechanism thereby during movement thereof to the retracted position so as to be energized for continued movement to a recoil position after the operating mechanism reaches the retracted position, said charging mechanism comprising a handle reciprocable between a forward and a rearward position, a pawl pivotally mounted to the operating mechanism for engagement by said handle during movement to the rearward position to transmit rearward movement of said handle to rearward movement of the operating mechanism, cam means for disengaging said pawl from said handle when the operating mechanism is in the retracted position, a spring biased against said pawl for simultaneously biasing said pawl to a position to be engaged by said handle and the operating mechanism to the forward position, and a bar to engage said handle to the bolt for S" transferring rearward movement of said handle to the bolt for actuation thereof to the recoil position after the operating mechanism is disengaged from said handle.

3. In a firearm, the combination of an operating rod actuatable to a retracted position responsive to operation of the firearm, a bolt energizeable by said operating rod for continued movement to a recoil position after said operating rod reaches the retracted position, a reciprocable handle, means engaging said handle to said operating rod for manual retraction thereof, means for disengaging said handle from said operating rod when in the retracted position, and a bar to engage said handle to said bolt for completion of the recoil thereof by said handle after said operating rod is disengaged therefrom.

4. In a firearm having a bolt reciprocable between a latch battery position and a recoil position, an operating rod for unlatching the bolt and initiating the recoil thereof responsive to operation of the firearm, a handle for manually operating said operating rod and for providing a supporting means for the front of the firearm, a pawl means pivotally mounted on said operating rod for detachably engaging said handle with said operating rod, driving means for transmitting rearward movement of said handle to recoil movement of the bolt, and means for disengaging said pawl means from said handle when said operaing rod is in said retracted position for completion of the recoil of the bolt by said handle.

5. In a firearm having a receiver and a barrel, a bolt reciprocable between a battery and a recoil position in the receiver, a gas cylinder member and a tubular member fixed to the front end of the receiver parallel to the axis of the barrel, an operating rod slidably mounted in said gas cylinder for actuation from an inoperative to a retracted position responsive to operation of the firearm and engaged with said bolt for initiating the recoil thereof, a sleeve member slidingly mounted on said tubular member, an arm extending from said sleeve member, a pawl device pivotally mounted to said operating rod for engagement by said arm to transfer rearward movement of said arm to said operating rod, cam means for disengaging said pawl means from said arm when said operating rod is in the retracted position, a spring for simultaneously biasing said operating rod to the inoperative position and said pawl device to a position to be engaged by said arm, bar means cooperable with said sleeve for urging said bolt to the recoil position after said arm is disengaged from said operating rod, and a handle fixed to said sleeve for operation thereof and for means of supporting the front of the firearm.

6. In a firearm having a receiver and a barrel, a bolt reciprocable between a latched battery position and a recoil position in the receiver, a gas cylinder member and a tubular member fixed to the front end of the receiver parallel to the axis of the barrel, an operating rod slidably mounted in said gas cylinder for reciprocation between a retracted and an inoperative position and engaged with said bolt for initiating the recoil thereof re sponsive to the operation of the firearm, a slot extending through said operating rod for communication with a longitudinal opening in said gas cylinder, a pawl device pivotally mounted to said operating rod in said slot, a lug portion on said pawl device extendable outwardly through said opening, a longitudinal bore extending from the rear of said operating rod to said slot, a spring receivable by said bore and being engageable with said pawl device for simultaneously biasing said lug portion through said opening and said operating rod to the inoperative position, a sleeve member slidably mounted on said tubular member, an arm extending from said sleeve for engagement with said lug to transfer rearward movement of said sleeve to said operating rod, a cam portion on said lug cooperable with one end of said opening for urging said lug against the bias of said spring out of engagement with said arm when said operating rod is in the retracted position, bar means cooperating with said sleeve for continuing the movement of said bolt to the recoil position by said sleeve after said arm is disengaged from said pawl device, and handle means for operating said sleeve and providing front support means for the firearm.

7. In a firearm having a receiver and a barrel, a bolt reciprocable between a latched battery position and a recoil position in the receiver, a gas cylinder member and a tubular member fixed to the front end of the receiver parallel to the axis of the barrel, an operating rod slidably mounted in said gas cylinder for reciprocation between a retracted position and an inoperative position and engaged with said bolt for initiating the recoil thereof during movement to the retracted position, a slot extending through said operating rod for communication with a longitudinal opening in said gas cylinder, a pawl device pivotally mounted to said operating rod in said slot, a lug portion projecting from said-pawl device for extension through said opening, a longitudinal bore extending from the rear end of said operating rod to said slot, a spring receivable by said bore to engage said pawl device for simultaneously biasing said operating rod from said retracted position to said inoperative position and said lug through said opening, a sleeve member slidably mounted on said tubular member, means for biasing said sleeve member to a forward position on said tubular member, handle means for moving said sleeve, a spring-biased latch for releasably locking said handle in a forward firearm supporting position, an arm extending from said sleeve for engagement with said lug to transfer rearward movement of said handle to said operating rod, a cam portion on said pawl device cooperable with the rear end of said opening for urging said lug against the bias of said spring out of engagement with said arm when said operating rod is in said retracted position, a bracket fixed to said sleeve and provided with a channel, a bar slidably mounted in said channel and engaged to the rear end with the front end of said bolt, a first lug positioned on said bar member for engagement by said bracket when said pawl device is disengaged from said arm to transfer rearward movement of said handle to said bolt, and a second lug positioned in said bar to be engageable by said bracket for returning said driving member to a normal position during the return of said handle to a forward position.

8. A charging mechanism for a firearm having a reciprocable operating device movable from an inoperative position to a retracted position responsive to operation of the firearm and a reciprocable bolt having engagement with the operating device during movement thereof to the retracted position for acceleration to a recoil position after the operating device stops in the retracting position, said charging mechanism comprising a reciprocable handle, means on said handle for manually actuating the operating device to the retracted position, means for disengaging said handle from the operating device when in the retracted position, and means cooperable with said handle for continuing the movement of the bolt to the recoil position after the operating mechanism stops in the retracted position.

9. A charging mechanism for a firearm having a reciprocable operating device movable from an inoperative position to a retracted position responsive to operation of the firearm and a reciprocable bolt having engagement with the operating device during movement thereof to the retracted position for acceleration of the bolt to a recoil position after the operating device stops in the retracted position, said charging mechanism comprising a handle reciprocable between a forward and a rearward position, a first means cooperable with said handle for retracting the operating mechanism to the retracted position, and means for disengaging said first means from said handle when the operating mechanism is in the retracted position, and a second means cooperable with said handle for actuating the bolt to the recoil position during continned movement of said handle to the rearward position, and for continuing to move the bolt to the recoil position.

10. A charging mechanism for a firearm having a reciprocable operating device actuatable from an inoperative position to a retracted position responsive to operation of the firearm and a reciprocable bolt having engagement with the operating device during movement thereof to the retracted position for acceleration to a recoil position after the operating device stops in the retracted position, said charging mechanism comprising a handle reciprocable between a forward and a rearward position, means cooperable with said handle for actuating the operating device to the retracted position during initial movement of said handle from. said forward position, means for disengaging the operating device from said handle when the operating device is in theretracted position and said handle is between the forward and rearward positions, and means for moving the bolt to the recoil position during con tinned movement of said handle to the rearward position.

11. A charging mechanism for a firearm having an operating mechanism reciprocable between an inoperative and a retracted position and a reciprocating bolt energizeable by the operating mechanism for movement from a battery to a recoil position during joint movement of the operating mechanism and the bolt to the retracted position of the operating mechanism, said charging mechanism comprising a handle reciprocable between a forward and a reaward position, latching means cooperable with said handle for actuating the operating mechanism to the retracted position during initial movement of said handle from said forward position, cam means for disengaging the operating mechanism from said handle when the operating mechanism is in the retracted position and said handle is between said forward and rearward positions, means for moving the bolt to the recoil position during continued movement of said handle to said rearward position, and spring means for returning said handle to said forward position.

12. A charging mechanism for a firearm having a reciprocable operating device actuatable from an inoperative to a retracted position responsive to operation of the firearm and a reciprocable bolt engaged with the operating device during actuation thereof to the retracted position for acceleration to a recoil position after the operating device reaches the retracted position, said charging mechanism comprising a handle reciprocable between a forward position and a rearward position, a first means cooperable with said handle for actuating the operating mechanism to the etracted position, a second means cooperable with said handle for actuating the bolt to the recoil position after said first means has moved the bolt from the locked battery position, and cam means for disengaging said first means from said handle when the operating mechanism is in the retracted position and said handle is between said forward and rearward positions, and spring means for returning said handle to the forward position.

References Cited in the file of this patent UNITED STATES PATENTS 814,242 Smith Mar. 6, 1906 1,083,872 Berthier Ian. 6, 1914 2,071,020 Boussel Feb. 16, 1937 2,104,033 Green Ian. 4, 1938 2,413,104 Goepfrich Dec. 24, 1946 

